Modern electronics, such as smart phones, personal digital assistants, location based services devices, enterprise class servers, or enterprise class storage arrays, are packing more integrated circuits into an ever shrinking physical space with expectations for decreasing cost. Contemporary electronics expose integrated circuits and packages to more demanding and sometimes new environmental conditions, such as cold, heat, and humidity requiring integrated circuit packages to provide robust structures.
Numerous technologies have been developed to meet these requirements. Some of the research and development strategies focus on new technologies while others focus on improving the existing and mature technologies. Research and development in the existing technologies may take a myriad of different directions. One direction is an increase in integrated circuit density and an integration of more circuit elements with the integrated circuits.
Faster, more reliable, and higher-density circuits, produced at lower cost, are the goals for the entire integrated circuit (IC) industry. Circuit elements, such as capacitors, are used for various integrated circuit applications. For example, making metal-insulator-metal (MIM) capacitors can be used for analog applications, mixed signal (analog/digital circuits) applications, and radio frequency (RF) circuits. These circuit elements, such as capacitors, may also serve as decoupling circuits to provide improved voltage regulation, programmability, and noise immunity.
Previous generations of semiconductor technology, these capacitors are integrated into the integrated circuits when the integrated circuit devices are formed on the substrate. For example, the MIM capacitors may be fabricated using interconnecting metal patterns (e.g., Al/Cu) used to connect the individual integrated circuit elements, such as field effect transistors (FETs).
In the past, metal layers used to fabricate the MIM capacitors and similar circuit elements have typically been a material such as aluminum. However, the temperature coefficient of expansion of aluminum and similarly employed materials leads to parameter control problems. For example, the use of aluminum can result in the formation of bumps or hillocks of various dimensions and configurations making it difficult to control the electrical parameters of capacitors made using it. In addition, formation of hillocks may also destroy or adversely affect the parameters of the circuit elements. These problems lead to yield loss, field failures, reliability problems, or a combination thereof.
Thus, a need still remains for an integrated circuit system providing low cost manufacturing, improved yield, and improved reliability for the MIM circuit elements. In view of the ever-increasing need to save costs and improve efficiencies, it is more and more critical that answers be found to these problems.
Solutions to these problems have been long sought but prior developments have not taught or suggested any solutions and, thus, solutions to these problems have long eluded those skilled in the art.